Salt Crystals Experiments

We did this fun experiment in our classroom last week and let the crystals grow for a week. It was fun and it goes along with our unit on Rocks and Minerals. Here are some samples of our cool Salt Crystals experiment.

I used a briquette and then we cut little evergreen tree shapes out of cardstock and glued them on bowls next to the briquettes. Then we added solution and food coloring to both. And let them sit for a few days. This is after about 2 days.

We sent home the directions for our experiments too. We also looked at salt crystals and sugar crystals under viewers on black paper and did some Water Jelly Crystal experiments too. Fun!


I have this book in my class. I tell the kids all about this old timer photographer who took old fashioned photos
of snowflakes and proved that no 2 were exactly alike when their crystals formed. I also have a copy of
his book, where he photographed hundreds of snowflakes. It was interesting to share. Our crystals kind of look like snow or snowflakes.

This one turned out the prettiest with all the colors of the rainbow and some pretty good growth. All the kids made one and took it home.  

I searched for lots of experiment ideas on the internet for this newly developed unit. I’ve not had to teach rocks before. But I think we learned a lot about them.  Check out my 3 Types of Rocks Flapbooks we made too. They are cool.

Here they are ready to take them home after a week. They looked pretty cool. We talked about gems 
and crystals and how they are found in metamorphic rocks which are under a lot of heat and pressure. That’s how
diamonds and many expensive gem jewels are made. 

 This was right after we had mixed the solution and added food coloring to our salt crystals experiment. It is salt, ammonia and laundry bluing.

Here they are after about 24 hours….lots of stuff growing and a little liquid still left….. We just left them on the
counter and kids could view them several times a day. Everybody had their own. 
Here they are after a weekend….a few still had some sediments in the bottom.

 But most of them were purely crystals by then….really interesting to see all the different colors and formations…..

This salt crystal formation was really freaky looking. Lea ended up with a really pretty purple and blue one. I think they look a lot more interesting growing on the cardstock “tree” instead of on the charcoal briquette. Next year I think we will do trees in a clear cup. That would be maybe better for transporting home too. 

Check these flap books out HERE. There is also a cool video on The Rock Cycle check it out!  HERE.

It was a fun bunch of experiments. We still have to do the layers of the earth in clay. That will be our last bit of the ROCK UNIT. It’s been such a cool earth science unit to study. The kids learned A LOT!